func handleConnections(conn *websocket.Conn) {
    // Make sure we close the connection when the function returns
    defer conn.Close()

    userName, err := getUsernameFromConn(conn)
    if err != nil {
        log.Fatal(err)
        return
    }

    fmt.Println("Hello *** user ", userName)
    salutionNewUser(userName, broadcast)

    // Register our new client
    addConn(conn, userName)

    // TODO: fix lock
    // if isItNewUser(conn, userName) {
    //  fmt.Println("Hello *** user ", userName)
    //  salutionNewUser(userName, broadcast)
    // }

    go listeningMsgs(conn, broadcast)
}

func listeningMsgs(conn *websocket.Conn, broadcastCh chan Message) {
    for {
        var msg Message
        // Read in a new message as JSON and map it to a Message object
        // err := ws.ReadJSON(&msg)     // gorilla
        err := websocket.JSON.Receive(conn, &msg)
        if err != nil {
            log.Printf("error: %v", err)
            removeConn(conn, userName)
            return
        }

        storedUserName, err := getUsernameFromConn(conn)
        if storedUserName != msg.Username {
            log.Fatal("Warning: stored-username and message-author mismatch. Connection will be refused.")
            removeConn(conn, userName)
            return
        }

        // Add connectionId to the message
        mu.Lock()
        msg.ConnID = clients[conn]
        mu.Unlock()

        // Send the newly received message to the broadcast channel
        broadcastCh <- msg
        fmt.Println(msg.Username, "> ", msg.Text)
    }
}